Can someone smarter than me help figure out my projected compression ratio. 383 elcheapador budget build

[4mulas]

I’ve seen calculators online but not sure if I’m using them right. Can someone help out with figuring the compression ratio for me?

The info:

-383 .020 over, so 4.27 bore
-Pistons sit .037 down in the hole
-Using felpro head gaskets (blue ones in the mopar engine tear down kits) which I think are known to be .044 or maybe .039 (somewhere in that range)
-Piston are neither domed nor dished. Flat top I suppose. Just an elcheapador cast piston like silvolite maybe or equivalent.
-Using a 516 closed chamber head with the exhaust valves enlarged to 1.74. (not sure if changing the valves reduces affects the chamber volume)
-I have 452 heads as well in case i should save the 516’s for a future 440 build??? Ie, if the gains aren’t worth using the 516’s I could swap in 452’s

As an aside I have 2 choices of cams. Which one would yah use?
-New no name Elgin style white box cam .444 214 duration@.050 intake, and .467 224 duration@.050 exhaust with 112cl OR:
-A used comp 270H which is .470 lift and 224 duration@.050 on both intake and exhaust with 110 cl

Holley street dominator intake

Car has power brakes.

Notes: I have all this crap sitting around and am just putting something together on the cheap to get rolling while I carefully think out a 440 build, so please don’t tell me such and such is crap or you wouldn’t do that etc….

I have the SA Gear double roller timing set pictured, not sure if advancing or retarding with cam is recommended by you guru’s? Or just straight up. I think the choices are 4 degrees either way. Or do I just have to degree it to see where it’s at?

Thank you in advance !

 

[copper67sat]

I use Summit's calculator. You need to cc your heads to get chamber volume. Also need to know your actual head gasket thickness or calculate it both ways to see the variation. I assumed 80cc chamber volume and 0.039 compressed gasket thickness in the calculator below. Says 9.1:1 based on those dimensions.

 

[PRHeads]

Without knowing the chamber volume, anything you come up with is just a guess.
But assuming the heads are 78cc, you’d be at around 9.0cr.
Heads @84cc and it’s more like 8.6cr.

 

[ruffcut]

You will have to know the cc's of the heads to get a calculated compression.

 

[j-c-c-62]

You will have to know the cc's of the heads to get a precise calculated compression.

For your situation, with everything else you already know, a guess might be good enough.

 

[R413]

Here is my guess, buy some sreel shim head gaskets and use the 516 head and the small cam.

Don't use an offy or a wieand intake, use a DP4B, a performer or a stock one.

 

[4mulas]

Without knowing the chamber volume, anything you come up with is just a guess.
But assuming the heads are 78cc, you’d be at around 9.0cr.
Heads @84cc and it’s more like 8.6cr.

Agreed. I read in several places the 516’s were around 76-79 ish. Wasn’t sure there either.

Are 906 and 452 84cc? Or more? Thank you